They weren't buried .. they fell out of pockets and gradually went into the ground (if you find them singley). In the mid-1800's, many pants had no pockets at all and the size of some of them wore through the pockets that were there. One of the best places for metal detector guys looking for coins is at cemetaries, old picnic areas, churches, and other gathering places where people either lost coins from relaxing/playing or pulling handkerchiefs out of there pockets with change adhering to them. I doubt if many of the tokens were buried, but you'd be surprised to see the number of coins, just lost, that work their way into the ground.